Operator configurable preferred network and radio access technology selection for roaming multi-rat capable devices

ABSTRACT

A multi-RAT capable wireless device and a method for execution in a multi-RAT capable wireless device are provided. The wireless device maintains a registration history of all wireless network,RAT combinations through which the wireless device has previously attempted to register with data communication service registration point. Upon an event triggering network registration, the wireless device identifies a set of available wireless network,RAT combinations, selects an available wireless network,RAT combination from the set of available wireless network,RAT combinations having regard to the registration history and a preferred network,RAT combination list stored at the wireless device and attempts to register with the data communication service registration point through the available wireless network,RAT combination that has been selected. If the attempt is successful, the wireless device receives an update to the preferred network,RAT combination list and updates the preferred network,RAT combination list stored at the wireless device.

FIELD OF THE INVENTION

The present disclosure relates to network selection for multimode ormulti-RAT capable devices.

BACKGROUND

Prior to receiving any services from a network operator, a roamingwireless device must select a network from one or more availablenetworks. Multi-RAT (Multi Radio Access Technology) capable wirelessdevices operating in regions with overlaying Multi-RAT networks pose afurther problem for roaming. For example, a Multi-RAT wireless devicecapable of supporting CDMA (Code Division Multiple Access) and GSM(Global System for Mobile communications) radio access technologies mayroam to a region covered by one or more CDMA networks and one or moreGSM networks.

It may be that, for example, due to roaming agreements between theoperator of the wireless device's home network and the networkoperator(s) of the available networks in the wireless device's currentgeographic location, CDMA is the current preferred RAT in the wirelessdevice's current geographic location. However, in another geographiclocation, for example, in another country, the preferred RAT may be GSM.

Since roaming agreements can change quite dynamically, a hardcoded liststored on a wireless device during production or sale is typically notan ideal solution. Furthermore, since a multi-RAT capable wirelessdevice is capable of operating according to two or more standardsrespectively associated with the two or more RATs with which it iscapable of operating, it is not typically possible to use standardspecific mechanisms for optimal roaming.

Many wireless devices are capable of both voice and data communication.However, not all of the networks that are available in the currentlocation of a wireless device may support both voice and datacommunications. For example, an older legacy network may be availablethat only supports voice calling, but cannot support datacommunications, such as e-mail or web browsing.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the disclosure will now be described in greater detailwith reference to the accompanying drawings, in which:

FIG. 1A is a block diagram of a wireless system featuring a multi-RATcapable wireless device and a plurality of wireless networks utilizingvarious RATs;

FIG. 1B is a block diagram of the wireless device shown in FIG. 1A;

FIG. 2 is a block diagram of a multi-RAT wireless system interfaced witha data communication service registration point;

FIG. 3 is a flowchart of a method of wireless network,RAT combinationselection; and

FIG. 4 is a block diagram of another wireless device.

DETAILED DESCRIPTION

According to one broad aspect, there is provided a method for executionin a multi-RAT (multi-Radio Access Technology) capable wireless device,the method comprising: maintaining a registration history of allwireless network,RAT combinations through which the wireless device haspreviously attempted to register with a data communication serviceregistration point; upon an event triggering network registration,identifying a set of available wireless network,RAT combinations;selecting an available wireless network,RAT combination from the set ofavailable wireless network,RAT combinations having regard to theregistration history and a preferred network,RAT combination list storedat the wireless device; attempting to register with the datacommunication service registration point through the available wirelessnetwork,RAT combination that has been selected; if the attempt toregister with the data communication service registration point throughthe available wireless network,RAT combination that has been selected issuccessful, receiving an update to the preferred network,RAT combinationlist stored at the wireless device; and updating the preferrednetwork,RAT combination list stored at the wireless device.

In some embodiments, the method further comprises: updating theregistration history based on the attempt to register with the datacommunication service registration point through the available wirelessnetwork,RAT combination that has been selected.

In some embodiments, the method further comprises: if the attempt toregister with the data communication service registration point throughthe available wireless network,RAT combination that has been selected isunsuccessful, selecting an available wireless network,RAT combinationfrom the set of available wireless network,RAT combinations havingregard to the preferred network,RAT combination list and the updatedregistration history.

In some embodiments, maintaining a registration history comprises atleast one of: maintaining an identification of network,RAT combinationsthrough which the wireless device has previously attempted and failed toregister with the data communication service registration point; andmaintaining an identification of network,RAT combinations through whichthe wireless device has previously attempted and succeeded inregistering with the data communication service registration point.

In some embodiments: maintaining an identification of network,RATcombinations through which the wireless device has previously attemptedand failed to register with the data communication service registrationpoint comprises maintaining a blacklist identifying such network,RATcombinations; and maintaining an identification of network,RATcombinations through which the wireless device has previously attemptedand succeeded in registering with the data communication serviceregistration point comprises maintaining a registration list identifyingsuch network,RAT combinations;

In some embodiments, selecting an available wireless network,RATcombination from the set of available wireless network,RAT combinationscomprises: avoiding selecting an available wireless network,RATcombination from the set of available wireless network,RAT combinationsthat is included in the blacklist.

In some embodiments, selecting an available wireless network,RATcombination from the set of available wireless network,RAT combinationscomprises: preferentially selecting an available wireless network,RATcombination from the set of available wireless network,RAT combinationsthat is included in both the preferred network,RAT combination list andthe registration list.

In some embodiments, the preferred network,RAT combination listidentifies relative preferences for network,RAT combinations identifiedtherein.

In some embodiments, receiving an update to the preferred network,RATcombination list stored at the wireless device comprises: receiving aMCC-dependent (Mobile Country Code-dependent) update to the preferrednetwork,RAT combination list that is dependent on a MCC of thenetwork,RAT combination that has been selected.

In some embodiments, the MCC-dependent update identifies preferredwireless network,RAT combinations having the same MCC as the network,RATcombination that has been selected.

In some embodiments, the MCC-dependent update further identifiespreferred wireless network,RAT combinations having a MCC associated witha country that neighbors a country associated with the MCC of thenetwork,RAT combination that has been selected.

In some embodiments, receiving an update to the preferred network,RATcombination list stored at the wireless device comprises: receiving anupdate generated based on contents of a preferred list repository.

In some embodiments: the update to the preferred network,RAT combinationlist is included as part of a registration response from the datacommunication service registration point; and receiving the updatecomprises receiving the registration response.

In some embodiments: the registration history comprises a record of alast registered network,RAT combination; and selecting an availablewireless network,RAT combination from the set of available wirelessnetwork,RAT combinations having regard to the registration history andthe preferred network,RAT combination list stored at the wireless devicecomprises selecting the last registered network,RAT combination if thelast registered network,RAT combination is included in the set ofavailable wireless network,RAT combinations.

In some embodiments, the preferred network,RAT combination list storedat the wireless device identifies preferred wireless network,RATcombinations by MCC (Mobile Country Code), MNC (Mobile Network Code) andRAT type.

In some embodiments, the preferred network,RAT combination list storedat the wireless device further identifies preferred wireless network,RATcombinations by at least one of Location Area Indicator (LAI) andRouting Area Indicator (RAI).

In some embodiments, the registration history identifies wirelessnetwork,RAT combinations by MCC (Mobile Country Code), MNC (MobileNetwork Code) and RAT type.

In some embodiments, the update to the preferred network,RAT combinationlist is dependent on the multi-RAT capability of the wireless device.

In some embodiments, the method further comprises: determining if theupdated preferred network,RAT combination list includes an availablewireless network,RAT combination that is more preferred than thewireless network,RAT combination that has been selected; and upondetermining that the updated preferred network,RAT combination listincludes an available wireless network,RAT combination that is morepreferred than the wireless network,RAT that has been selected,re-selecting from the set of available wireless network,RAT combinationshaving regard to the updated preferred network,RAT combination list andthe registration history.

According to a second broad aspect, there is provided a computerreadable medium having computer executable instructions stored thereonfor execution on a wireless device so as to implement the methodaccording to the first aspect described above.

According to a third broad aspect, there is provided a multi-RAT(multi-Radio Access Technology) capable wireless device comprising: atleast one antenna; a memory for storing a preferred network,RATcombination list and a registration history of wireless network,RATcombinations through which the wireless device has previously attemptedto register with a data communication service registration point; amulti-RAT capable wireless access radio functionally connected to the atleast one antenna that, upon an event triggering network registration,identifies available wireless network,RAT combinations; a network,RATcombination selector that: selects an available wireless network,RATcombination from the set of available wireless network,RAT combinationshaving regard to the registration history and the preferred network,RATcombination list; attempts to register the wireless device with the datacommunication service registration point through the available wirelessnetwork,RAT combination that has been selected; and if the attempt toregister with the data communication service registration point throughthe available wireless network,RAT combination that has been selected issuccessful: receives an update to the preferred network,RAT combinationlist; and updates the preferred network,RAT list.

In some embodiments, the network,RAT combination selector updates theregistration history based on the attempt to register with the datacommunication service registration point through the available wirelessnetwork,RAT combination that has been selected.

In some embodiments, if the attempt to register with the datacommunication service registration point through the available wirelessnetwork,RAT combination that has been selected is unsuccessful, thenetwork,RAT combination selector selects an available wirelessnetwork,RAT combination from the set of available wireless network,RATcombinations having regard to the preferred network,RAT combination listand the updated registration history.

In some embodiments, the registration history comprises at least one of:a blacklist of network,RAT combinations through which the wirelessdevice has previously attempted and failed to register with the datacommunication service registration point; and a registration list ofnetwork,RAT combinations through which the wireless device haspreviously attempted and succeeded in registering with the datacommunication service registration point.

In some embodiments, the network,RAT combination selector avoidsselecting an available wireless network,RAT combination from the set ofavailable wireless network,RAT combinations that is included in theblacklist.

In some embodiments, the network,RAT combination selector preferentiallyselects an available wireless network,RAT combination from the set ofavailable wireless network,RAT combinations that is included in both thepreferred network,RAT combination list and the registration list.

In some embodiments, the preferred network,RAT combination listidentifies relative preferences for network,RAT combinations identifiedtherein.

In some embodiments: the network,RAT combination selector attempts toregister with the data communication service registration point bygenerating a registration request that identifies a MCC (Mobile CountryCode) of the wireless network,RAT combination that has been selected.

In some embodiments: the registration history comprises a record of alast registered network,RAT combination; and the network,RAT combinationselector is configured to select the last registered network,RATcombination if the last registered network,RAT combination is includedin the set of available wireless network,RAT combinations.

In some embodiments, the preferred network,RAT combination list storedat the wireless device identifies preferred wireless network,RATcombinations by MCC (Mobile Country Code), MNC (Mobile Network Code) andRAT type.

In some embodiments, the preferred network,RAT combination list storedat the wireless device further identifies preferred wireless network,RATcombinations by at least one of a Location Area Indicator (LAI) and aRouting Area Indicator (RAI).

In some embodiments, the registration history identifies wirelessnetwork,RAT combinations by MCC (Mobile Country Code), MNC (MobileNetwork Code) and RAT type.

In some embodiments, the network,RAT combination selector is configuredto: determine if the updated preferred network,RAT combination listincludes an available wireless network,RAT combination that is morepreferred than the wireless network,RAT combination that has beenselected; and upon determining that the updated preferred network,RATcombination list includes an available wireless network,RAT combinationthat is more preferred than the wireless network,RAT that has beenselected, re-select from the set of available wireless network,RATcombinations having regard to the preferred network,RAT combination listand the registration history.

Other aspects and features of the present disclosure will becomeapparent, to those ordinarily skilled in the art, upon review of thefollowing description of the specific embodiments of the disclosure.

In the following detailed description of sample embodiments, referenceis made to the accompanying drawings, which form a part hereof, and inwhich is shown by way of illustration specific sample embodiments inwhich the present invention may be practised. These embodiments aredescribed in sufficient detail to enable those skilled in the art topractice the invention, and it is to be understood that otherembodiments may be utilized and that logical, mechanical, electrical,and other changes may be made without departing from the scope of theinvention. The following detailed description is, therefore, not to betaken in a limiting sense, and the scope is defined by the appendedclaims.

Wireless communication systems may be constructed to operate inaccordance with operating specifications determined by astandard-setting regulatory body.

Many operating standards have been developed and continue to bedeveloped and corresponding cellular communication systems have beenimplemented as these new standards are developed, resulting in asignificant portion of the populated area of the world being potentiallyserviced by one or more generations of wireless communication systems.

Network infrastructures of multiple generations, i.e., RATs, of wirelesscommunication systems might, for example, be installed such that theirservice areas overlay a common area and can be concurrently operatedover the common area. Furthermore, separate networks of the same RATmight be operated concurrently by separate network operators over acommon area.

A wireless device may be authorized to communicate using a particularwireless communication system through the purchase of a servicesubscription with the network operator of the wireless communicationsystem. In cases such as this, the wireless device is usually associatedwith a home network, which is typically the network that providescoverage over an area in which the user of the wireless device isanticipated most regularly to be operated. However, as wireless devicesare inherently mobile, the wireless device might roam beyond thecoverage area of its home network. When roaming beyond the home network,the wireless device might instead be positioned at a locationencompassed by another network.

Typically, when the wireless device roams beyond its home network, thewireless device is authorized to communicate by way of one or more ofthe visited networks, depending upon, among other things, whether thewireless device and the visited network operate pursuant to the sameRAT. In addition to simply RAT compatibility, agreements between thenetwork operators of the visited and home networks may affect whether ornot the wireless device is able to communicate by way of a particularvisited network.

The wireless device might roam into an area encompassed by more than onenetwork such that more than one visited network is available to thewireless device. The home network of the wireless device may operatewith a first RAT, while a roaming wireless device may encounter networksoperating with the same or different RATs while roaming outside thecoverage area of its home network. For example, a wireless device mayhave a service subscription with a North American CDMA wirelesscommunication system, which would mean that its home network isCDMA-based, but while roaming that wireless device might be located in ageographic region that is serviced by both CDMA and GSM networksoperated by network operators other than the wireless device's homenetwork operator. In such a situation, if the wireless device is amulti-RAT wireless device capable of communication with CDMA and GSMnetworks, the wireless device has the potential to select between all ofthe available CDMA and GSM networks, whereas a wireless device that isonly capable of CDMA-based operation would be limited to communicatingwith the available CDMA network(s).

In general, it may be advantageous for network operators to have somemechanism by which it would be possible to efficiently and dynamicallyspecify a preference for the RAT (radio access technology) and network,i.e. a network,RAT combination, that a roaming wireless device selectsto receive services over when roaming.

For a multi-RAT capable wireless device that is capable of both datacommunication and voice communication, it may be also be preferred thatthe multi-RAT capable wireless device avoid selecting a wireless networkwith which to register that is not capable of supporting both voice anddata communication.

Conventional mechanisms for selecting between available visited networkswhile roaming include the use of a preferred roaming list (PRL) forCDMA-based network. The PRL in CDMA-based network selection defines aset of preferred roaming partners, which is typically stored on theSubscriber Identity Module (SIM) of the wireless device, and is used incombination with signal strength scanning to select a preferred roamingpartner network from the preferred roaming list with the highestreceived signal strength.

Historically, the preferred roaming lists are based upon capability ofthe visited networks having voice capability pursuant tocircuit-switched connectivity. However, many late generation wirelesscommunication systems and wireless devices are capable ofpacket-switched communication services. This means that many newnetworks operating with newer RATs, such as CDMA and Global Packet RadioService (GPRS), provide access to packet data services while some olderlegacy networks provide only circuit-switched services.

When packet data communication services are to be used by a roamingmobile node, selection of the visited network through which tocommunicate based upon conventional criteria, i.e., based upon merelythe capability of a visited network to handle voice communications, isinadequate to ensure that a packet data communication service can beprovided in the selected network. Furthermore, even if the selection ofthe visited network is limited to selection from those visited networksthat are potentially capable of supporting a packet data communicationservice, it may be advantageous to avoid selecting a visited networkthat has previously been found to be unable to provide the desiredservice, even though it should have been capable of doing so based onits RAT capabilities.

When roaming, before a wireless device is able to make and receive voicecalls and/or send and receive data over a visited network, the cellularwireless device selects and registers with one of a plurality ofcommunication networks which are available within a given geographiccoverage area. After registering with the selected network, the wirelessdevice typically monitors a wireless communication channel of theselected network to monitor for its calls or messages.

Communication System

Referring first to FIG. 1A, shown is a block diagram of a wirelesssystem 50 featuring a multi-RAT capable wireless device 10 and aplurality of wireless networks 21,22,23,31,32. Wireless networks 21, 22and 23 provide partially overlapping service coverage in a first countryA associated with a first MCC (mobile country code) A, while wirelessnetworks 31 and 32 provide partially overlapping service coverage in asecond country B associated with a second MCC B. For illustrativepurposes, it is assumed that the multi-RAT wireless device 10 is capableof operating with three RATs, namely RAT A, RAT B and RAT C. RATs A andB, may, for example, be 2G GSM and 3G UMTS and RAT C may be CDMA.

In the illustrated example, it is assumed that each of the wirelessnetworks 21, 22, 23, 31 and 31 is a PLMN (Public Land Mobile Network).It is further assumed that: wireless network 21 operates using RAT A,e.g. 2G GSM; wireless network 22 operates using RAT C, e.g. CDMA;wireless network 31 operates using RATs A and B, e.g. 2G and/or 3G GSM,and wireless networks 23 and 32 operate using RAT A, RAT B and RAT C.However, more generally, each of the wireless networks 21, 22, 23, 31and 32 may be any appropriate wireless network operating with any numberof RATs, provided that each available network connection can be uniquelyidentified during registration. Examples of potential wireless networksin conjunction with which embodiments of the present disclosure might beused include, but are not limited to, GSM/Edge Radio Access Network(GERANs), Universal Mobile Telecommunications System Terrestrial RadioAccess Network (UTRANs), Evolved UMTS Terrestrial Radio Access Network(EUTRANs), Code Division Multiple Access 2000 (CDMA2000) Networks,Wireless Local Area Networks (WLANs) or Wireless Fidelity (WiFi)Networks, and Worldwide Interoperability for Microwave Access (WiMAX)Networks.

PLMN's are typically identified by a MCC (Mobile Country Code) and a MNC(Mobile Network Code). However, with reference to the illustratedexample, in order to uniquely identify the potential network,RATcombinations available via wireless networks 23, 31 and 32, which aremulti-RAT networks, a RAT identifier may be used in addition to the MCCand MNC of wireless networks 23, 31 and 32 in order to distinguishbetween the available network,RAT combinations.

For the purposes of this disclosure, it is assumed that the multi-RATcapable wireless device 10 is to be used to provide access to one ormore data communication services. In general, a data communicationservice is any service that provides communication of data to and from awireless device over an available wireless network capable of providingsaid service. Often, this communication of data takes the form of packetdata transmissions to and from the wireless device. However, it shouldbe understood that this disclosure is not limited to packet-based datacommunication services.

The data communicated service may be, for example, an e-mail service forcommunicating e-mail messages to and from the wireless device 10. Forsome data communication services, the wireless device 10 must registerwith a communication data service registration point, which may beassociated with the home network of the wireless device, each time thewireless device registers with a new network in order to receive properHRT (Host Routing Table) information for the communication data service.This communication data service registration point may function as adata relay through which data associated with the particularcommunication data service is relayed to the wireless device 10.

Referring to FIG. 2, shown is a block diagram of an arrangement of amulti-RAT wireless system 60 in communication with a data communicationservice registration point 70 via a communication link 80. The datacommunication service registration point 70 is in turn in communicationwith a preferred list repository 72 via a communication link 82.Preferred list repository 72 may be co-located with or integrated withthe data service communication registration point 70. The multi-RATwireless system 60 represents any number of wireless networks from oneor multiple operators providing communications through any number ofRATs. That is, the multi-RAT wireless system 60 may include any numberof network,RAT combinations through which a wireless device, such as thewireless device 10 shown in FIGS. 1A and 1B (described below), maypotentially attempt to register with the data communication serviceregistration point 70 to receive the data communication service.

The preferred list repository 72 contains one or more lists definingpreferred network,RAT combinations on a per MCC-basis or on a per regionbasis, where a region typically encompasses geographical locations frommultiple countries, i.e., multi-MCC. For one or more of the MCCs orregions there may be a separate list for different classifications ofsubscribers. For example, a network operator may sell a “World Roamer”subscription plan and an “Economy” subscription plan and may wish toprovide a different preferred network,RAT combination list to thosedifferent types of subscribers in one or more MCCs or regions.

In some embodiments, the preferred list repository 72 includes ahierarchy of lists, with a “master” list that identifies the preferrednetwork,RAT combination list that is to be used in each MCC or regionfor different subscriber types. Table 1 provides an example of how asection of such a “master” list for MCC 310 might be represented.

TABLE 1 Subscriber Type MCC Preferred List Identifier World Roamer 310List_1 Subscriber Economy Subscriber 310 List_2

As can be seen from the section of the exemplary “master” list in Table1, subscribers of the “World Roamer” type would receive preferredNetwork,RAT combination list “List_1” when successfully registered withthe data communication service registration point 70 through anetwork,RAT combination associated with MCC 310.

In some embodiments, the preferred list repository 72 may store a“global” list for each network operator identifying the networkoperator's roaming partners in all known MCCs in which the networkoperator has at least one roaming partner. However, “Global” updates,i.e., transmitting the entire “global” is likely to require morebandwidth than MCC-dependent or region-dependent updates, i.e.,transmitting the preferred network,RAT combinations associated with aparticular MCC or region.

Typically, a registration response is sent to a wireless device from thedata communication service registration point 70 in response to thewireless device's registration with the data communication serviceregistration point each time the wireless device registers with a newnetwork,RAT combination within the multi-RAT wireless system 60. In someembodiments, this registration response includes a list of preferrednetwork,RAT combinations for the wireless device to use while roaming.

The list of preferred network,RAT combinations may be retrieved from thepreferred list repository 72 for inclusion as part of the registrationresponse from the data communication service registration point 70 tothe wireless device.

The preferred network,RAT combination list from the communication dataservice registration point 70 is used to update a preferred network,RATcombination list stored at the wireless device, which the wirelessdevice uses as part of its network,RAT combination selection process. Inthis way, any updates to the preferred network,RAT combination list arepropagated to the wireless devices each time they register with the datacommunication service registration point associated with theirrespective home networks in order to receive the data communicationservice.

In some embodiments, the preferred network,RAT combination list is notincluded in a registration response from the data communication serviceregistration point 70, rather another wireless communication element(not shown) that is in communication with the preferred list repository72 and the data communication service registration point 70 may retrievethe preferred network,RAT list from the preferred list repository 72 andtransmit it to the wireless device once the data communication serviceregistration point 70 notifies the wireless communication element thatthe wireless device successfully registered with the data communicationservice registration point. In such embodiments, the data communicationservice registration point 70 may not be in communication with thepreferred list repository 72.

In addition to the updating of the preferred network,RAT combinationlist provided by the network operator of a wireless device's homenetwork, this disclosure also utilizes the concept of selecting anavailable network,RAT combination based on the success and/or failure ofprevious attempts to register with the data communication serviceregistration point through the available networks. To this end, awireless device in accordance with the disclosure maintains aregistration history of attempts to register the wireless device withthe data communication service registration point. The registrationhistory may include an identification of network,RAT combinationsthrough which the wireless device has attempted and failed to registerwith the data communication service registration point and/or anidentification of network,RAT combinations through which the wirelessdevice has succeeded in registering with the data communication serviceregistration point.

The identification of network,RAT combinations through whichregistration has failed may be implemented as a blacklist thatidentifies said network,RAT combinations through which the wirelessdevice has attempted and failed to register with the data communicationservice registration point, while the identification of network,RATcombinations through which registration has succeeded may be implementedas a registration list that identifies said network,RAT combinationsthrough which the wireless device has successfully register with thedata communication service registration point. Only the results of themost recent attempt to register with the data communication serviceregistration point is included in the registration history for any givennetwork,RAT combination. For example, if a previous attempt to registerwith the data communication service registration point through a givennetwork,RAT combination was successful, then that success would be notedby identifying the given network,RAT combination in the registrationlist to indicate that the wireless device had successfully registeredwith the data communication service registration point through the givennetwork,RAT combination. However, if a subsequent attempt to registerwith the data communication service registration point through the samenetwork,RAT combination failed, the failure would be noted by adding anidentification of the network,RAT combination to the blacklist and theinclusion of the network,RAT combination in the registration list wouldbe removed. Correspondingly, removal of a network,RAT combination fromthe blacklist and addition to the registration list may be performed ifa first attempt to register with the data communication serviceregistration point through the network,RAT combination fails but a laterattempt succeeds.

The registration history may be persisted at the wireless device for atleast the duration in which the wireless device is located within ageographic region associated with a current MCC. In other words, in someembodiments, while roaming in a country other than that in which awireless device's home network is located, the wireless device maymaintain a history of successes/failures to connect to the datacommunication service through the available networks in the roamingcountry and base it's network,RAT combination selection at least in parton this history, such that the wireless device avoids attempting toconnect to networks through which it has previously failed to connect tothe data communication service. This history of successes/failures maybe realized by maintaining a “blacklist” of networks/RATs over which thewireless device has attempted and failed to connect to a datacommunication service and a separate list of networks/RATs over whichthe wireless device has attempted and succeeded to connect to the datacommunication service.

In some embodiments, the blacklist is network,RAT combination-specific,which means that it identifies not only the network, typically using MCCand MNC, but also a RAT identifier to uniquely identify the network,RATcombination over which the failed attempt to register with thecommunication data service registration point was made. For example,with reference to FIG. 1A, if the wireless device 10 attempts and failsto register with a data communication service registration point usingRAT B over wireless network 23, in some embodiments, the wireless device10 would then add an entry to its blacklist identifying RAT B (via a RATidentifier corresponding to RAT B) of wireless network 23 (via MCC andMNC of wireless network 23).

Example details of the wireless device 10 are shown in FIG. 1B. Thewireless device 10 has a multi-RAT wireless access radio 11, a processor12, a network,RAT combination selector 13 and a memory 14. The wirelesssystem 50 and the wireless device 10 may have other components, but theyare not shown for sake of simplicity. In some embodiments the memory 14may include a SIM (Subscriber Identity Module).

Operation of the wireless device 10 will now be described first by wayof detailed example with reference to FIGS. 1A, 1B and 2. Followingthis, flow charts of example functionality of the wireless device 10will be described.

The memory 14 is used to store lists of network,RAT combinations, whichare used in network,RAT combination selection. The lists of network,RATcombinations include a registration history 16 and a preferrednetwork,RAT combination list 15. The preferred network,RAT combinationlist 15 is provided and updated OTA (Over The Air) followingregistration with a data communication service registration point asdescribed herein.

In the illustrated example, the registration history 16 includes ablacklist 17 of network,RAT combinations through which the wirelessdevice 10 has previously attempted and failed to register with a datacommunication service registration point, and a registration list 18 ofnetwork,RAT combinations through which the wireless device haspreviously succeeded in registering with a data communication serviceregistration point. The blacklist 17 and the registration list 18 aremaintained and updated in the memory 14 by the processor 12.

The network,RAT combination selector 13 of the wireless device 10performs network,RAT combination selection of a network,RAT combinationfrom a set of available network,RAT combinations based on the preferrednetwork,RAT combination list and the registration history 16. Ingeneral, in order to select a candidate network,RAT combination from aset of available network,RAT combinations that have been identified, thenetwork,RAT combination selector 13 utilizes the preferred network,RATcombination list 15 to determine which, if any, of the availablenetwork,RAT combinations are preferred, and their level of preferencerelative to one another.

In some embodiments, the set of available network,RAT combinations isdetermined using the multi-RAT wireless access radio 11 to determinereceived signal strength indicators (RSSIs) of network,RAT combinationsoperating in the current geographical location of the wireless device10.

The network,RAT combination selector 13 utilizes the registrationhistory 16 to potentially improve the likelihood of selecting anetwork,RAT combination through which the wireless device 10 will beable to register with a data communication service registration point.For example, if the registration history 16 includes the blacklist 17 ofnetwork,RAT combinations through which the wireless device 10 haspreviously attempted and failed to receive data service, the network,RATcombination selector 13 may avoid selecting any available network,RATcombination that is included in the blacklist 17. Similarly, if theregistration history 16 includes the registration list 18 of network,RATcombinations through which the wireless device 10 has previouslysucceeded in receiving data service, the network,RAT combinationselector 13 may preferentially select an available network,RATcombination that is included in both the preferred network,RATcombination list 15 and the registration list 18.

In order to receive data communication service, the wireless device 10must connect to the wireless communication service through an availablenetwork capable of providing access to the data communication service inthe wireless device's current geographical location.

While operating in regions in which the home network of the wirelessdevice 10 provides access to the communication data service, the networkoperator of the wireless device's home network typically prefers thatthe wireless device registers with and receives services through thehome network. However, in regions in which the home network of thewireless device 10 is unable to provide coverage, for example, when thewireless device is roaming, it is generally preferred that the wirelessdevice registers with, and receives access to the data communicationservice through, a visited network operated by a network operator withwhich the network operator of the wireless device's home network has apreferred roaming agreement.

The preferred roaming agreement between the home network operator andthe visited network operator can potentially reduce the costs associatedwith receiving services through the visited network for the wirelessdevice's user. However, as noted above, roaming agreements betweennetwork operators can change often and therefore a static preferrednetwork,RAT combination list could potentially lead to network,RATcombination selection that results in the selection of a visited networkwith a roaming agreement that is currently less preferred than anotheravailable visited network due to changing roaming agreements that arenot reflected in the static preferred list. Accordingly, embodiments ofthe present disclosure include OTA updating of a preferred network,RATcombination list when a wireless device, such as the wireless device 10shown in FIGS. 1A and 1B, registers with a data communication serviceregistration point in order to receive the data communication service.

With reference to FIG. 2, the wireless device 10 re-registers with thedata communication service registration point 70 to receive the datacommunication service each time the wireless device registers with a newnetwork,RAT combination. A network operator may submit changes to thepreferred network,RAT combination lists that are stored in the preferredlist repository 72 for the wireless devices with subscription servicesto the operator's network. The changes to the preferred network,RATcombination list for a wireless device, which may have been submitted bythe wireless device's home network operator due to changes in one ormore roaming agreements, are then propagated to the wireless device whenthe wireless device next registers with the data communication serviceregistration point 70. A network operator may update the preferred listrepository 72 by interfacing with it through the data communicationservice registration point 70 or some other interface device (not shown)in order to update the preferred network,RAT combination list(s) storedin the preferred list repository. For example, with reference to Table1, a network operator associated with the section of the “master” listshown in Table 1 could potentially change the preferred network,RATcombination list for “Word Roamer” subscribers for MCC 310 by eitherchanging “List_1” or by changing the list that is pointed to for “WorldRoamer” subscribers for MCC 310, e.g., the “List_1” entry could bereplaced with an entry that points to “List_1_NEW”.

In some embodiments, the multi-RAT capabilities of the mobile device 10may be taken into consideration during updating of the preferredNetwork,RAT combination list stored on the wireless device 10. Forexample, in some embodiments, prior to the OTA transmission of thepreferred network,RAT combination list to the wireless device 10, thelist may be edited to remove non-applicable RATs. That is, network,RATcombinations that are not supported by the wireless device 10 may beremoved from the preferred network,RAT list prior to transmission.Alternatively, preferred network,RAT combination lists that are specificto different permutations and combinations of RAT capabilities may bestored in the preferred list repository, rather than dynamically editinga common preferred network,RAT list prior to transmission of the list.

In some embodiments, a common list is transmitted to each wirelessdevice, and the wireless device 10 is configured to ignore networksoperating with RATs that it cannot support.

In some embodiments, when registering with the data communicationservice registration point, the wireless device 10 identifies the MCCassociated with the network,RAT combination through which the wirelessdevice 10 is attempting to register with the data communication serviceregistration point as part of its registration attempt, which allows anMCC-dependent update of the preferred network,RAT combination list to beprovided to the wireless device 10 OTA via the data communicationservice, for example, from the data communication service registrationpoint 70 via communication link 80 for the embodiment shown in FIG. 2.That is, in some embodiments, an updated preferred network,RATcombination list is provided to the wireless device 10 based on the MCCof the network,RAT combination through which the wireless device 10registers with the data communication service registration point 70 toreceive the data communication service.

In some embodiments, the update to the preferred network,RAT combinationlist may only include preferred network,RAT combinations having the sameMCC as that associated with the network,RAT combination through whichthe wireless device 10 has registered with the data communicationservice registration point 70.

In some embodiments, the updated preferred network,RAT combination listmay also include network,RAT combinations having MCCs associated withcountries that neighbour the country in which the network,RATcombination through which the wireless device 10 has registered with thedata communication service registration point 70 is located.

The foregoing two approaches can potentially reduce the amount of datathat must be communicated OTA to the wireless device 10 in order toupdate the preferred network,RAT combination list stored thereon. Insome embodiments, if bandwidth concerns are not an issue, updates forall potential roaming regions could be provided to the wireless device10 when the wireless device 10 connects to the data communicationservice.

For illustrative purposes, it is assumed that countries A and B are notthe home country of the wireless device 10 and that the wirelessnetworks 21, 22, 23, 31 and 32 are not the home network of the wirelessdevice. It is also assumed that RAT A is a circuit switched (CS) RATcapable of providing voice service, e.g. 2G GSM, RAT B is a packetswitched (PS) RAT capable of providing data service, e.g. 3G GSM/UMTS,RAT C is capable of providing both voice and data service, e.g. CDMA,and the multi-RAT wireless access radio 11 of the multi-RAT wirelessdevice 10 is capable of communicating via RAT A, RAT B and RAT C.

In the illustrated example, it is further assumed that the networkoperator of the home network of the wireless device 10 has roamingagreements with the operators of wireless networks 22, 23 and 32.However, it is further assumed that the preference for network 32 incountry B has occurred subsequent to the wireless device's lastregistration with a data communication service registration point, andas such the preferred network,RAT combination list 15 stored in thememory 14 of the wireless device initially identifies the relativepreference for networks 22 and 23. Table 2 provides an example of aportion of such a preferred network,RAT combination list.

TABLE 2 Preferred Network, RAT Combination List Preference MCC MNCPreferred RAT 1 MCC A PLMN 23 RAT B 2 MCC A PLMN 23 RAT C 3 MCC A PLMN22 RAT C

It should be noted that the preferred network list stored in the memory14 of the wireless device 10 includes at least the following fields:

Preference/Priority (ordering);

MCC;

MNC; and

Preferred RAT.

The MCC and MNC identify a PLMN, but the inclusion of the Preferred RATfield indicates the RAT that is preferred for a multi-RAT PLMN.

The preferred network,RAT combination list shown in Table 2 may havebeen transmitted to the wireless device 10 the last time the wirelessdevice registered with a data communication service registration point,in accordance with the present disclosure.

When the wireless device 10 is powered on, or when the wireless device10 loses coverage, the wireless device 10 will attempt to register withan available network. In the illustrated example, it is assumed that thewireless device 10 is powered on by its user after moving to its currentlocation in country A from a position outside the coverage area of thePLMNs 21, 22, 23. Once powered on, the wireless device 10 identifiesavailable wireless network,RAT combinations and finds that there arethree available wireless networks in its present area, namely PLMNs 21,22, and 23, offering five wireless network,RAT combinations, namely PLMN23,RAT A, PLMN 23,RAT B, PLMN 23,RAT C, PLMN 21,RAT A and PLMN 22,RAT C.

In some embodiments, the registration history 16 includes a record ofthe last network,RAT combination that the wireless device 10 wasregistered with. This record may, for example, be included in theregistration list 18. In such embodiments, the network,RAT combinationselector 13 may check the registration history 16 in the memory 14 todetermine if the wireless device 10 was last registered to any of theavailable wireless network,RAT combinations. As noted above, for thepurposes of this example it has been assumed that the wireless device 10has been powered on by its user after moving to its current location incountry A from a position outside the coverage area of the PLMNs21,22,23. As such, it is assumed that the wireless device 10 was lastoperated outside of the coverage area of the PLMNs 21,22,23 andtherefore the wireless device 10 was not last registered with any of thenetwork,RAT combinations that have been identified as currentlyavailable to the wireless device 10. This could be determined by thenetwork,RAT combination selector 13 by comparing a record in theregistration history 16 of the last network,RAT combination that thewireless device was registered with to the set of available network,RATcombinations that have been identified for its current location incountry A.

In some embodiments, once the network,RAT combination selector 13determines that the last registered network,RAT combination is notcurrently available, the network,RAT combination selector 13 selects oneof the available network,RAT combinations having regard to the preferrednetwork,RAT combination list 15 and the registration history 16 storedin the memory 14 of the wireless device 10.

For the purposes of this example, it is assumed that the wireless device10 has not blacklisted any of the available network,RAT combinationsavailable in its current location in country A. That is, the blacklist17 that is part of the registration history 16 stored in the memory 14of the wireless device 10 does not identify any of the currentlyavailable network,RAT combinations as being blacklisted. Forillustrative purposes, Table 3 provides an example of an emptyblacklist.

TABLE 3 Blacklist MCC MNC RAT

In some embodiments, in order to determine if an available network,RATcombination is blacklisted, the network,RAT combination selector 13determines if the available network,RAT combination is listed in theblacklist 17. Since the example blacklist shown in Table 3 is empty,i.e., does not identify any of the available network,RAT combinations,the network,RAT combination selector 13 determines that none of theavailable network,RAT combinations are blacklisted. In some embodiments,the network,RAT selector 13 avoids attempting to register with anavailable network,RAT combination that has been blacklisted.

In some embodiments, the registration history 16 stored in the memory 14of the wireless device 10 also includes a registration list 18, which isused to maintain a history of network,RAT combinations through which thewireless device has successfully registered with a data communicationservice registration point.

For the purposes of this example, it is assumed that the registrationlist 18 is initially empty, and therefore does not identify any of theavailable network,RAT combinations. Table 4 provides an example of anempty registration list in accordance with an embodiment of thisdisclosure.

TABLE 4 Registration List MCC MNC RAT

Having regard to the preferred network,RAT combination list 15, which isassumed to include the preferences identified in Table 2, and theregistration history 16, which is assumed to include an empty blacklist17, such as the blacklist shown in Table 3, and an empty registrationlist 18, such as the registration list shown in Table 4, the network,RATcombination selector 13 determines that RAT B of PLMN 23 is thepreferred network,RAT combination to register with in its currentlocation.

Once the network,RAT combination selector 13 has selected network,RATcombination PLMN 23,RAT B as described above, the wireless device 10attempts to register with a data communication service registrationpoint, such as the data communication service registration point 70shown in FIG. 2, through the network,RAT combination (PLMN 23, RAT B)that has been selected.

If the wireless device 10 succeeds in registering with the datacommunication service registration point through RAT B of PLMN 23, thewireless device receives an OTA update to its preferred network,RATcombination list 15.

In some embodiments, the update to the preferred network,RAT combinationlist is provided by the data communication service registration point,which may retrieve the update from a preferred list repository, such asthe preferred list repository 72 shown in FIG. 2.

In some embodiments, the update to the preferred network,RAT combinationlist 15 is based on the MCC of the network through which the wirelessdevice 10 is currently registered, which in this case would be MCC A ofPLMN 23.

If the attempt to register with the data communication serviceregistration point 70 through PLMN 23,RAT B is successful, the wirelessdevice 10 may update the registration list 18 with an entry indicatingthat the wireless device 10 successfully registered with the datacommunication service registration point 70 through RAT B of PLMN 23.

In some embodiments, an updated preferred network,RAT combination listmay not be provided by the preferred list repository 72 if the wirelessdevice 10 already has an up-to-date preferred network,RAT combinationlist. This may be achieved, for example, by having a “version” numberassociated with each preferred network,RAT combination list update andby only providing the update if a newer version than that currentlystored at the wireless device 10 is available. The wireless device 10could identify the “version” number of its current preferred network,RATlist as part of its registration with the data communication serviceregistration point 70. Alternatively, the data communication servicepoint 70 could maintain a record of what the last update was that wastransmitted to the wireless device 10 and would only transmit a furtherupdate to the wireless device 10 when one becomes available.

In some embodiments the update to the preferred network,RAT combinationlist may be entries that are appended to the preferred network,RATcombination list stored at the wireless device 10 and/or may overwritesome but not all of the entries in the preferred network,RAT combinationlist stored at the wireless device 10.

In some embodiments, the update to the preferred network,RAT combinationlist includes a replacement network,RAT combination list that completelyoverwrites the preferred network,RAT combination list that is stored atthe wireless device 10. This latter method can potentially keep thepreferred network,RAT combination that is stored at the wireless device10 small.

Table 5 provides an example of an updated version of the registrationlist shown in Table 4, which has been updated to identify a successfulregistration with the data communication service registration pointthrough PLMN 23,RAT B.

TABLE 5 Registration List MCC MNC RAT MCC A PLMN 23 RAT B

Alternatively, if the wireless device 10 fails to 5 register with thecommunication data service registration point 70 through the network,RATcombination that has been selected (PLMN 23,RAT B), the wireless devicemay blacklist RAT B of PLMN 23 by updating the blacklist 17 stored inmemory 14 with an entry including the MCC, MNC and RAT 10 identifiercorresponding to RAT B of PLMN 23. Table 6 provides an example of howthe blacklist shown in Table 3 may be updated to identify RAT B of PLMN23 if the attempt to register with the data communication serviceregistration point through RAT B of PLMN 23 is unsuccessful.

TABLE 6 Blacklist MCC MNC RAT MCC A PLMN 23 RAT B

The registration list 18 and the blacklist 17 may be maintained in thememory 14 indefinitely, or may only be maintained until the wirelessdevice 10 registers in a new location with a different MCC.

In some embodiments, the blacklist 17 is cleared after every preferrednetwork,RAT combination list 15 update.

In some embodiments, the wireless device 10 is configured to display thepreferred network,RAT combination list 15 to a user of the device toallow manual user selection of a preferred network,RAT combination fromthe list.

In some embodiments, the wireless device 10 is configured to allow auser of the device to manually clear the blacklist 17.

Assuming that the wireless device 10 has succeeded in connecting to thedata communication service through RAT B of PLMN 23 and has received anMCC-dependent update to its preferred network,RAT combination list 15,in some embodiments the wireless device 10 then checks to see if theupdated preferred network list indicates that one of the other availablenetworks, namely PLMNs 21 or 22, is now more preferred (according to theupdated preferred network list 15) than RAT B of PLMN 23.

Table 7A provides an example of the preferred network,RAT combinationlist shown in Table 2 after an update is received that indicates PLMN22,RAT C is now more preferred than PLMN 23,RAT B or PLMN 23,RAT C.

TABLE 7A Preferred Network, RAT Combination List Preference MCC MNCPreferred RAT 1 MCC A PLMN 22 RAT C 2 MCC A PLMN 23 RAT B 3 MCC A PLMN23 RAT C

This change in preferred network may have resulted, for example, from achange in the roaming agreements between the operator of the wirelessdevice's home network and the operators of one or more of the availablenetworks PLMNs 21, 22, 23. In the illustrated example, it has beenassumed that RAT A does not support data communication, and thereforethe wireless device cannot register with the data communication serviceregistration point through either PLMN 23, RAT A or PLMN 21, RAT A. Itshould be noted that the preferred network,RAT combination list 15 doesnot contain either of those network,RAT combinations, as they areincapable of supporting data communication. However, in someembodiments, the preferred network,RAT combination list 15 may includethose network,RAT combinations as the least preferred network,RATcombinations, although omitting them can potentially reduce the size ofthe OTA transmission of the update to the preferred network,RATcombination list 15.

In some embodiments, the preferred network,RAT combination list 15updates may include updates for a region that includes more than onecountry. For example, when the wireless device 10 registers with thedata communication service registration point 70 through a network,RATcombination in a first country, it may receive an updated preferrednetwork,RAT combination list that includes preferences for the firstcountry as well as one or more neighbouring countries that are part ofthe same region as the first country. For example, a region may bedefined that includes Germany and France, such that when the wirelessdevice 10 registers in either Germany or France the wireless device 10is provided with a list of the preferred network,RAT combinations forboth Germany and France. With reference to the specific examplediscussed above with reference to FIG. 1A, in some embodiments a regionthat includes both Country A and Country B might be defined, such thatwhen the wireless device 10 receives an update to its preferrednetwork,RAT combination list 15 while operating in Country A, the updateincludes preferred network,RAT combinations for both Country A andCountry B.

Table 7B provides an example of the preferred network,RAT combinationlist shown in Table 2 after an update is received that indicates PLMN22,RAT C is now more preferred than PLMN 23,RAT B or PLMN 23,RAT C inCountry A and PLMN 32,RAT C is preferred over PLMN 32,RAT B in CountryB.

TABLE 7B Preferred Network, RAT Combination List Preference MCC MNCPreferred RAT 1 MCC A PLMN 22 RAT C 2 MCC A PLMN 23 RAT B 3 MCC A PLMN23 RAT C 1 MCC B PLMN 32 RAT C 2 MCC B PLMN 32 RAT B

Region-based updates can potentially be beneficial, as the wirelessdevice can be made aware of changes to network,RAT combinationpreferences in neighbouring countries before actually attempting tooperate in one of the neighbouring countries.

Assuming that the preferred network,RAT combination list 15 has beenupdated as shown in Table 7A and now indicates that RAT C of PLMN 22 ismore preferred than RAT B of PLMN 23, in some embodiments, thenetwork,RAT combination selector 13 will attempt to register with PLMN22 using RAT C, and if successful will then attempt to re-register withthe data communication service registration point through PLMN 22,RAT C.Alternatively, the wireless device 10 may remain registered with PLMN23,RAT B until it is powered down or RAT B of PLMN is incapable ofproviding the data communication service, for example, if the wirelessdevice 10 moves out of the coverage region of PLMN 23.

If the attempt to re-register with the data communication serviceregistration point through PLMN 22,RAT C is successful, then thewireless device may update the registration list 18 to include anidentification of the successful registration through PLMN 22,RAT C.Table 8 is an example of how the registration list shown in Table 5 maybe updated after a successful registration with the data communicationservice registration point through PLMN 22,RAT C.

TABLE 8 Registration List MCC MNC RAT MCC A PLMN 22 RAT C MCC A PLMN 23RAT B

In situations where the preferred network,RAT combination list 15 storedin the memory 14 does not indicate a preference for one of the availablenetworks, the network,RAT combination selector 13 might initially selectone of the available network,RAT combinations based on some suitablecriterion, for example RSSI (Received Signal Strength Indication). Sucha situation may arise, for example, when the wireless device 10 is firstturned on in a new coverage region associated with an MCC for which thewireless device 10 has not yet received an update to its preferrednetwork,RAT combination list 15, or in situations where network,RATcombinations are equally preferred, e.g. equal preference ranking, inthe preferred network list. In some cases, a network operator may wishto substantially balance their roaming subscribers between equallypreferred network,RAT combinations. For embodiments in which preferenceis indicated by the ordering of the preferred network,RAT combinationlist, which prevents equal ranking, a separate list may be provided foreach of the equally preferred network,RAT combinations that respectivelylist one of the equally preferred network,RAT combinations as the mostpreferred. In some embodiments, each separate list has a respective oneof the equally preferred network,RAT combinations ordered first in itslist of preferred network,RAT combinations. In some embodiments, theseseparate lists may be equally distributed amongst subscribers, so that asubstantially equal number of subscribers receive each respective list.

Subsequent to registering with one of the PLMNs 22, 23, as describedabove, it is assumed that the wireless device 10 is moved to anothergeographical region located in country B (associated with MCC B) asindicated by arrow 40. The movement causes the wireless device 10 tolose coverage and therefore another registration is triggered. Thewireless device 10 identifies available wireless network,RATcombinations in its new location in country B and finds that there aretwo available wireless networks in its new area, namely PLMNs 31 and 32offering five available network,RAT combinations, namely PLMN 31,RAT A,PLMN 31,RAT B, PLMN 32,RAT A, PLMN 32,RAT B and PLMN 32,RAT C.

For illustrative purposes, it is assumed that prior to moving to countryB, the wireless device 10, while operated in country A, first attemptedand succeeded in registering with a data communication serviceregistration point through PLMN 23,RAT B, at which point the wirelessdevice received an update to its preferred network,RAT combination listand based on that update re-registered with the data communicationservice registration point through PLMN 22,RAT C as described above.That is, for the purposes of this example it is assumed that when thewireless device 10 is moved from country A to country B the preferrednetwork,RAT combination list 15, blacklist 17 and registration list 18stored in the memory 14 of the wireless device are as shown in Tables7A, 3 and 8, respectively.

In some embodiments, the network,RAT combination selector 13 determinesif the wireless device 10 was last registered to any of the availablewireless network,RAT combinations by comparing the set of availablenetwork,RAT combinations to a record of the last registered network,RATcombination stored in the memory 14. Since the wireless device 10 waslast operated in country A outside the coverage of the network,RATcombinations available in country B, the wireless device 10 cannotregister with the last registered wireless network,RAT combination,which in the assumed scenario would be PLMN 22,RAT C.

In some cases, the wireless device 10 may have previously received apreferred network,RAT combination list 15 for country B. This may, forexample, have been stored in memory when the wireless device 10 wasfirst issued, or may have been updated OTA as described above, eitherduring a previous period of operation in country B, or as part of apreferred network,RAT combination list 15 update from the datacommunication service while visiting a neighbouring country. Forexample, in some embodiments, the preferred network,RAT combination list15 update that the wireless device 10 received when it connected to thedata communication service through RAT B of PLMN 23 may have included apreferred network,RAT combination list 15 update for both country A (MCCA) and country B (MCC B). This type of multi-country update may bepreferred for neighbouring countries so that wireless devices are awareof the preferred networks in their current location as well as those inthe neighbouring countries into which they may be likely to roam.

For illustrative purposes, it is assumed that the network operator ofthe home network of the wireless device 10 has a preferred roamingagreement with the operator of PLMN 32, but that neither PLMN 31 norPLMN 32 are indicated as preferred in the preferred network,RATcombination list currently stored in the memory 14 of wireless device10.

Once the network,RAT combination selector 13 determines, having regardto the preferred network,RAT combination list 15 (assumed to be as shownin Table 7A) and the registration history 16 (assumed to includeblacklist 17 and registration list 18 as shown in Tables 2 and 7,respectively) stored in memory 14, that none of the wireless network,RATcombinations available in its current location in country B arepreferred or blacklisted, the network selector 13 automatically selectsan available wireless network,RAT combination for registration based onanother suitable criteria, for example, on the respective RSSI of theavailable network,RAT combinations.

If it is assumed that the wireless device 10 registers with PLMN 31,RATB based on RSSI, the wireless device 10 will attempt to register with adata communication service registration point through RAT B of PLMN 31.The data communication service registration point that the wirelessdevice attempts to register with while in country B may be the same ordifferent than the data communication service registration point thatthe wireless device attempts to register with while in country A.

In some embodiments, the wireless device 10 transmits a registrationrequest to the data communication service registration point 70 thatincludes the MCC of the network,RAT combination through which thewireless device 10 is attempting to register with the data communicationservice registration point 70, e.g. MCC B, so that the datacommunication service registration point 70 is aware of the MCC of thenetwork,RAT combination through which the wireless device 10 isattempting to register with the data communication service registrationpoint 70. As described above, the data communication serviceregistration point 70 provides an update to the preferred network,RATcombination list 15 stored in the memory 14 of the wireless device 10.

In some embodiments, the update to the preferred network,RAT combinationlist 15 may be MCC-dependent, i.e., based on the MCC of the network,RATthrough which the wireless device 10 registers with the datacommunication service registration point 70.

If the attempt to register with the data communication serviceregistration point 70 through PLMN 31,RAT B is successful, the wirelessdevice 10 updates the registration list 18 to reflect this. Table 9shows an example of how the registration list 18 shown in Table 8 mightbe updated to include PLMN 31,RAT B.

TABLE 9 Registration List MCC MNC RAT MCC B PLMN 31 RAT B MCC A PLMN 22RAT C MCC A PLMN 23 RAT B

Assuming that the update to the wireless device 10 received anMCC-dependent update to its preferred network,RAT combination list 15after registering with the data communication service registration point70 through PLMN 31,RAT B, and that the update indicated that that PLMN32,RAT C is the preferred network,RAT combination in country B, in someembodiments the network,RAT combination selector 13 then attempts toregister with PLMN 32,RAT C after determining that PLMN 31,RAT B, withwhich the wireless device 10 is currently registered, is not thepreferred network,RAT combination in country B based on the updatedpreferred network,RAT combination list 15. Table 10 is an example of howthe preferred network,RAT combination list shown in Table 7A may beupdated after the wireless device receives the update to the preferrednetwork,RAT combination list 15.

TABLE 10 Preferred Network, RAT Combination List Preference MCC MNCPreferred RAT 1 MCC A PLMN 22 RAT C 2 MCC A PLMN 23 RAT B 3 MCC A PLMN23 RAT C 1 MCC B PLMN 32 RAT C 2 MCC B PLMN 32 RAT B

As can be seen in Table 10, it is assumed that the update to thepreferred network,RAT combination list 15 for country B (MCC B)indicates that PLMN32, RAT C is the most preferred network,RATcombination in country B, followed by PLMN 32,RAT B. With reference toTable 7B, it should be noted that the updated preferred network,RATcombination list shown in Table 10 could potentially have been providedto the wireless device 10 while operating in Country A usingregion-based updating of the preferred network,RAT combination list 15.That is, had the preferred network,RAT combination list 15 been updatedas shown in Table 7B while the wireless device 10 was operating inCountry A, the wireless device 10 would already have been aware of thepreference for PLMN 32,RAT C over PLMN 32,RAT B before relocating toCountry B. This could potentially have avoided attempts to firstregister with less preferred network,RAT combinations in Country B.

If the attempt to register with the data communication serviceregistration point 70 through PLMN 32,RAT C is not successful, thewireless device 10 may blacklist PLMN 32,RAT C by adding anidentification of PLMN 32,RAT C to the blacklist 17. Table 11 shows anexample of how the blacklist shown in Table 3 may be updated to maintaina record of a failed attempt to register with the data communicationservice registration point 70 through PLMN 32,RAT C.

TABLE 11 Blacklist MCC MNC RAT MCC B PLMN 32 RAT C

Having stored in memory 14 a record of the successful attempt toregister with the data communication service registration point 70through PLMN 31,RAT B and the unsuccessful attempt through PLMN 32,RATC, as reflected in the update in the registration list shown in Table 9and the update in the blacklist shown in Table 11, the network,RATcombination selector 13 may avoid attempting to register with PLMN32,RAT C at the next event triggering registration and instead attemptto register with PLMN 32,RAT B, despite the fact that PLMN 32,RAT C maybe indicated in the preferred network,RAT combination list 15 as beingpreferred by the wireless device's home network operator.

In some embodiments, having failed to register with the datacommunication service registration point 70 through PLMN 32,RAT C, thenetwork,RAT combination selector 13 may next attempt to register withthe data communication service registration point 70 through PLMN 32,RATB having regard to the fact that the preferred network,RAT combinationlist 15 indicates that PLMN 32,RAT B is the next most preferrednetwork,RAT combination in its current location in country B, as shownin Table 10. However, in some embodiments, if PLMN 31,RAT B wereindicated to be of an equal preference to PLMN 32,RAT B in the preferrednetwork,RAT combination list 15, the network,RAT combination selectorwould preferentially select PLMN 31,RAT B having regard to theregistration list 18 shown in Table 9, which indicates that the datacommunication service registration point was previously successfullyregistered with through PLMN 31,RAT B.

In some cases it may be desirable to define different network,RATcombination preferences in different locations within a country. Forexample, it may be desirable to define a preference for Network X,RAT Bin Berlin and a preference for Network Y,RAT C in the rest of Germany.Accordingly, in some embodiments, the preferred network,RAT combinationlist 15 includes an identification of preferred network,RATcombination(s) in location areas that represent a subset of thegeographic region associated with an MCC. For example, in someembodiments, a LAI (location area indicator) and/or a RAI (routing areaindicator) may be included in the preferred network,RAT combination list15 to be used in conjunction with MNC (mobile network code) to allowpreferred network,RAT combinations to be specified with greatergeographical granularity than MNC in conjunction with MCC. For example,with reference to the specific example discussed above with reference toFIG. 1A, it may be that in some portion of country A that is associatedwith a first LAI (LAI_1), RAT C of PLMN 22 is preferred, while in therest of country A, RAT B of PLMN 23 and RAT C of PLMN 23 are preferredover RAT C of PLMN 22. These preferences could be provided to thewireless device 10 when updating the preferred network,RAT combinationlist by including an identification of LAI in the list, for example, asshown in Table 12.

TABLE 12 Preferred Network, RAT Combination List Preferred PreferenceMCC MNC LAI RAT 1 MCC A PLMN 23 LAI_2 RAT B 2 MCC A PLMN 23 LAI_2 RAT C3 MCC A PLMN 22 LAI_2 RAT C 1 MCC_A PLMN_22 LAI_1 RAT_C 2 MCC A PLMN 23LAI_1 RAT B 3 MCC A PLMN 23 LAI_1 RAT C

In the above example, it is assumed that the rest of country A (outsideof the area associated with LAI_1) is associated with a second LAI(LAI_2). More generally, a country associated with an MCC may includeany number of LAIs respectively associated with a corresponding portionof the country. While a location area indicator (LAI) is used to providefurther geographical granularity to the preferred network,RATcombination list shown in Table 12, more generally, any geographicalindicator of which a wireless device can be made aware that isassociated with an area of operation of one or more network,RATcombinations can potentially be used to define a preference fornetwork,RAT combination(s) in that area. For example, as noted above,MNC in conjunction with LAI and/or RAI might be used in some embodimentsto define more localized unique identifiers of network,RAT combinationsthan simply MNC in conjunction with MCC.

In the illustrated example, the registration history 16 of the wirelessdevice 10 includes a blacklist 17 and a registration list 18 that areseparate lists. However, in some embodiments, the functionality of theblacklist 17 and the registration list 18 may be implemented in a singlelist of network,RAT combinations through which the wireless device haspreviously attempted to register with the data communication serviceregistration point, which single list also includes a blacklistidentifier that indicates whether or not a network,RAT combinationidentified in the single list has been blacklisted.

In the illustrated example, the network,RAT combination selector 13 isimplemented as software and is executed on the processor 14. However,more generally, the RAT and network selector 13 may be implemented assoftware, hardware, firmware, or any appropriate combination thereof.Although shown as a single component, more generally, the RAT andnetwork selector 13 may have one or more components. The one or morecomponents may be integrated with other components. Also, functionalityof the RAT and network selector 13 might be combined with othercomponents. For example, in alternative implementations, the RAT andnetwork selector 13 and the multi-RAT wireless access radio 11 arecombined as a single component. Other implementations are possible.

An example method of multi-RAT wireless network,RAT combinationselection is described below with reference to FIG. 3.

Method of Multi-RAT Wireless Network,RAT Combination Selection

Referring now to FIG. 3, shown is a flowchart of an example method ofmulti-RAT wireless network,RAT combination selection. This method may beimplemented in a wireless device, for example by the network,RATcombination selector 13 of the wireless device 10 shown in FIG. 1B.Alternatively, this method may be implemented in any appropriatelyconfigured wireless device.

The execution of the method starts at step 3-1 in which a registrationhistory of wireless network,RAT combinations through which the wirelessdevice has previously attempted to register with a data communicationservice registration point is maintained.

Upon an event triggering registration, which might for example be whenthe wireless device is powered on, or when the wireless device losescoverage, at step 3-2 the wireless device identifies a set of availablewireless network,RAT combinations.

At step 3-3, the wireless device selects an available network,RATcombination from the set of available wireless network,RAT combinationshaving regard to the registration history and a preferred network,RATcombination list stored at the wireless device.

In some embodiments, the registration history includes a blacklist ofwireless network,RAT combinations through which the wireless device haspreviously failed in registering with the data communication serviceregistration point. At step 3-3, the wireless device may avoid selectingan available network,RAT combination that is included on its blacklist.In some embodiments, the wireless device may attempt to register with anavailable network,RAT combination that has been blacklisted if thepreferred network,RAT combination list has been updated subsequent itsinclusion in the blacklist.

In some embodiments, the registration history includes a registrationlist of wireless network,RAT combinations through which the wirelessdevice has previously successfully registered with the datacommunication service registration point. At step 3-3, the wirelessdevice having regard to its preferred network,RAT combination list andits registration list may preferentially select an available network,RATcombination that is included on both the preferred network,RAT list andthe registration list.

In some cases, the preferred network,RAT combination list may includetwo or more network,RAT combinations that have the samepreference/priority level. In this case, if two such network,RATcombinations were identified by the wireless device at step 3-2 (orbetween steps 3-8 and 3-9 as described below), and there is noindication in the registration history that one of the two network,RATcombinations would be more likely to successfully provide a connectionto the data communication service registration point for registrationtherewith, then at step 3-3 the wireless device might select between thetwo available network,RAT combinations of the highestpreference/priority level based on an additional suitable criteria, suchas RSSI.

At step 3-4, the wireless device attempts to register with the datacommunication service registration point through the wirelessnetwork,RAT combination that has been selected.

At step 3-5, the registration history is updated based on the result ofthe attempt to register with the data communication service registrationpoint through the wireless network,RAT combination that has beenselected.

In some embodiments, if the registration attempt was unsuccessful, theavailable network,RAT combination that has been selected is added to theblacklist. In addition to adding the network,RAT combination to theblacklist, any entry in the registration list identifying thenetwork,RAT combination may be removed. In this way, a record of aprevious success in registering with the data communication registrationpoint through a particular network,RAT combination is removed from theregistration list if a later attempt through the particular network,RATcombination fails. Similarly, an earlier failure recorded in theblacklist for a particular network,RAT combination may be removed iflater success in registering with the data communication serviceregistration point is achieved.

At step 3-6, if the registration attempt was unsuccessful, then themethod returns to step 3-3, so that the wireless device can selectanother wireless network,RAT combination from the set of availablewireless network,RAT combinations now having regard to the registrationhistory that was updated at step 3-5 and the preferred network,RATcombination list.

At step 3-6, if the registration attempt was successful, then the methodproceeds to step 3-7, in which the wireless device receives an update tothe preferred network,RAT combination list stored at the wirelessdevice. In some embodiments, this update is communicated from the datacommunication service registration point to the wireless device via thewireless network,RAT combination through which the wireless deviceregistered with the data communication service registration point.

In some embodiments, the update to the preferred network,RAT combinationlist is MCC-dependent and is provided based on the MCC of thenetwork,RAT combination through which the wireless device registeredwith the data communication service registration point.

In some embodiments, the update to the preferred network,RAT combinationlist is region-dependent and is provided based on the region in whichthe network,RAT combination through which the wireless device hasregistered with the data communication service registration point islocated. In these embodiments, a region may be defined by two or moreMCCs, such that a wireless device that registers with the datacommunication service registration point through a network,RAT having anMCC that is part of a region will receive an update to its preferrednetwork,RAT combination list that includes the preferred network,RATcombination(s) having MCCs that are part of the region.

The OTA transmission of the update of the preferred network,RATcombination list to the wireless device may be implemented using anysuitable protocol. Examples of potential protocols that might be usedinclude, but are not limited to, an extensible Markup Language (XML)representation of a preferred network,RAT combination list or portionthereof over HyperText Transfer Protocol (HTTP), e.g., an XMLrepresentation of a preference table such as that shown in any one ofthe tables shown above over HTTP, or a Type-Length-Value (TLV) sent overUser Datagram Protocol (UDP).

At step 3-7, the wireless device updates its preferred network,RATcombination list based on the update received at step 3-6.

In some embodiments, after having updated its preferred network,RATcombination list at step 3-8, the wireless device may remain registeredwith the network,RAT combination through which it successfullyregistered with the data communication service registration point untilanother event triggering network registration occurs, at which pointnetwork,RAT combination selection may begin again.

Alternatively, in some embodiments, after having updated its preferrednetwork,RAT combination list at step 3-8, the wireless device determinesat step 3-9 whether the updated preferred network,RAT combination listindicates that one or more of the available network,RAT combinationsfrom the set of available network,RAT combinations identified in step3-2, is more preferred than the available network,RAT combinationthrough which the wireless device is currently registered with the datacommunication service registration point.

In some embodiments, between steps 3-8 and 3-9 the wireless device againidentifies available wireless network,RAT combinations to update the setof available wireless network,RAT combinations identified at step 3-2.This can be advantageous if a wireless network,RAT combination hasbecome available, or if a previously available wireless network,RATcombination has become unavailable, between steps 3-2 and 3-8.

If, at step 3-9 it is determined that the set of available network,RATcombinations includes an available network,RAT combination that is morepreferred than the currently selected network,RAT combination, then themethod returns to step 3-3. In this way, the wireless device is promptedto automatically attempt to register with the most preferred network,RATcombination that it has not currently blacklisted whenever the wirelessdevice receives an update to the preferred network,RAT combination list,which means that not only can changes in the preferred network,RATcombination list be propagated to a wireless device on its nextregistration with the data communication service, but the wirelessdevice also immediately begins network,RAT combination selection basedon the updated list. Furthermore, bandwidth requirements associated withtransmitting updated network,RAT combination lists to the wirelessdevice can potentially be limited by providing MCC-dependent orregion-dependent updates, such that updated preferences for network,RATcombinations having a particular MCC are propagated to the wirelessdevice the next time the wireless device registers with a network,RATcombination having the particular MCC.

In some embodiment, if all of the available network,RAT combinationshave been blacklisted, the wireless device attempts to register on thebest available network,RAT combination based on radio conditions, suchas RSSI, and will function without data service until the user moves.Once the wireless device encounters new MNCs, i.e., once the availablenetwork,RAT combination list includes at least one new entry, thewireless device attempts to register with the data communication serviceregistration point on the “new” available network,RAT combination(s).

In some cases, certain network,RAT combination rejection causes mayindicate that the lack of service, e.g. the inability to provide aconnection to register with the data communication service registrationpoint, is temporary. In some embodiments, if a connectivity failure,either to a network,RAT combination or to the data communication serviceregistration point there through, is indicated to be temporary, then thenetwork,RAT combination is not added to the blacklist.

If at step 3-9 it is determined that the set of available network,RATcombinations does not include an available network,RAT combination thatis more preferred than the currently selected network,RAT combination orif all of the more preferred available network,RAT combinations havebeen blacklisted, then wireless device remains registered with thecurrently selected wireless network,RAT combination until an eventtriggering network registration occurs and network,RAT combinationselection is repeated.

In some cases, a wireless device may successfully register with anetwork,RAT combination but fail to be able to register with the datacommunication registration point through the network,RAT combination ormay successfully register with the data communication serviceregistration point but then subsequently lose that connection. In someembodiments, if failure cause codes associated with either the failedregistration attempt or the lost connection indicate that the failuremay be temporary, then the wireless device may retry on the samenetwork,RAT combination. However, if the failure cause codes indicatethat the failure may be indefinite or permanent, then the wirelessdevice may blacklist the network,RAT combination and retry with adifferent network,RAT combination having regard to the registrationhistory and the preferred network,RAT combination list.

In some embodiments, the registration history, which in some embodimentsincludes a blacklist and/or a registration list, is maintained while thewireless device remains in operation in a geographical locationdesignated by the MCC of the last registered network,RAT combination.For example, with reference to FIG. 1A, if the wireless device 10 failsto connect to the data communication service through RAT C of PLMN 32while in country B (designated by MCC B), then the wireless device may“blacklist” RAT C of PLMN 32, such that it avoids registering with RAT Cof PLMN 32 while continuing to operate in a geographical locationcovered by networks having MCC B.

In some embodiments, the blacklist of network,RAT combinations for aparticular MCC may be cleared or ignored at step 3-3 if the wirelessdevice determines that the MCC of the last registered network,RATcombination is different than the MCCs of the available network,RATcombinations identified at step 3-2. Effectively, this would “reset” theblacklist for a particular country (MCC) when the wireless deviceregisters with a network,RAT combination having a different MCC.

In some embodiments, the blacklist may only be “automatically” resetwhen the preferred network,RAT combination list is updated. In across-border scenario where the wireless device moves from a network,RATcombination having a first MCC to a network,RAT combination having asecond MCC, the preferred network,RAT combination list may not beupdated when the wireless device registers with the data communicationservice registration point through the second network,RAT combinationif, for example, the wireless device already has the most up-to-dateversion of the preferred network,RAT combination list for the secondMCC. Accordingly, under such a scenario, in some embodiments theblacklist stored on the wireless device would not be reset when thewireless device registers with the second network,RAT combination eventhough the second network,RAT combination has a different MCC than thefirst network,RAT combination with which the wireless device waspreviously registered.

Another Wireless Device

Referring now to FIG. 4, shown is a block diagram of another wirelessdevice 100 that may implement any of the wireless device methodsdescribed herein. The wireless device 100 is shown with specificcomponents for implementing features similar to those of the wirelessdevice 10 of FIG. 1B. It is to be understood that the wireless device100 is shown with very specific details for exemplary purposes only.

A processing device (a microprocessor 128) is shown schematically ascoupled between a keyboard 114 and a display 126. The microprocessor 128is a type of processor with features similar to those of the processor14 of the wireless device 10 shown in FIG. 1B. The microprocessor 128controls operation of the display 126, as well as overall operation ofthe wireless device 100, in response to actuation of keys on thekeyboard 114 by a user.

The wireless device 100 has a housing that may be elongated vertically,or may take on other sizes and shapes (including clamshell housingstructures). The keyboard 114 may include a mode selection key, or otherhardware or software for switching between text entry and telephonyentry.

In addition to the microprocessor 128, other parts of the wirelessdevice 100 are shown schematically. These include: a communicationssubsystem 170; a short-range communications subsystem 102; the keyboard114 and the display 126, along with other input/output devices includinga set of LEDs 104, a set of auxiliary I/O devices 106, a serial port108, a speaker 111 and a microphone 112; as well as memory devicesincluding a flash memory 116 and a Random Access Memory (RAM) 118; andvarious other device subsystems 120. The wireless device 100 may have abattery 121 to power the active elements of the wireless device 100. Thewireless device 100 is in some embodiments a two-way radio frequency(RF) communication device having voice and data communicationcapabilities. In addition, the wireless device 100 in some embodimentshas the capability to communicate with other computer systems via theInternet.

Operating system software executed by the microprocessor 128 is in someembodiments stored in a persistent store, such as the flash memory 116,but may be stored in other types of memory devices, such as a read onlymemory (ROM) or similar storage element. In addition, system software,specific device applications, or parts thereof, may be temporarilyloaded into a volatile store, such as the RAM 118. Communication signalsreceived by the wireless device 100 may also be stored to the RAM 118.

The microprocessor 128, in addition to its operating system functions,enables execution of software applications on the wireless device 100. Apredetermined set of software applications that control basic deviceoperations, such as a voice communications module 130A and a datacommunications module 130B, may be installed on the wireless device 100during manufacture. In addition, a personal information manager (PIM)application module 130C may also be installed on the wireless device 100during manufacture. The PIM application is in some embodiments capableof organizing and managing data items, such as e-mail, calendar events,voice mails, appointments, and task items. The PIM application is alsoin some embodiments capable of sending and receiving data items via awireless network 110. In some embodiments, the data items managed by thePIM application are seamlessly integrated, synchronized and updated viathe wireless network 110 with the device user's corresponding data itemsstored or associated with a host computer system. As well, additionalsoftware modules, illustrated as another software module 130N, may beinstalled during manufacture.

The flash memory 116 stores computer executable instructions forimplementing features similar to those of the network,RAT combinationselector 13 of the wireless device 10 shown in FIG. 1B. The flash memory116 also stores a preferred network,RAT combination list and aregistration history similar to those stored in the memory 14 shown inFIG. 1B. In some embodiments, the registration history stored in theflash memory 116 includes a blacklist and a registration list similar tothose shown in FIG. 1B. In some embodiments, the registration history,which may include a blacklist and a registration list, may be stored in118, since the registration history is typically less important topersist. In a specific implementation, the other module 130N of theflash memory 116 stores computer executable instructions that whenexecuted implement a notification initiator. Note that theimplementations described with reference to FIG. 4 are very specific forexemplary purposes.

Communication functions, including data and voice communications, areperformed through the communication subsystem 170, and possibly throughthe short-range communications subsystem 102. The communicationsubsystem 170 includes a receiver 150, a transmitter 152 and one or moreantennas, illustrated as a receive antenna 154 and a transmit antenna156. In addition, the communication subsystem 170 also includes aprocessing module, such as a digital signal processor (DSP) 158, andlocal oscillators (LOs) 160. The communication subsystem 170 having thetransmitter 152 and the receiver 150 is an implementation of a wirelessaccess radio with features similar to those of the multi-RAT wirelessaccess radio 11 of the wireless device 10 shown in FIG. 1B. In someembodiments, the communication subsystem 170 includes a separate antennaarrangement (similar to the antennas 154 and 156) and RF processingchip/block (similar to the Receiver 150, LOs 160 and Transmitter 152)for each RAT, although a common baseband signal processor (similar toDSP 158) may be used for baseband processing for multiple RATs. Thespecific design and implementation of the communication subsystem 170 isdependent upon the communication network in which the wireless device100 is intended to operate. For example, the communication subsystem 170of the wireless device 100 may be designed to operate with the Mobitex™,DataTAC™ or General Packet Radio Service (GPRS) mobile datacommunication networks and also designed to operate with any of avariety of voice communication networks, such as Advanced Mobile PhoneService (AMPS), Time Division Multiple Access (TDMA), Code DivisionMultiple Access (CDMA), Personal Communications Service (PCS), GlobalSystem for Mobile Communications (GSM), etc. Examples of CDMA include 1Xand 1x EV-DO. The communication subsystem 170 may also be designed tooperate with an 802.11 Wi-Fi network, and/or an 802.16 WiMAX network.Other types of data and voice networks, both separate and integrated,may also be utilized with the wireless device 100.

Network access may vary depending upon the type of communication system.For example, in the Mobitex™ and DataTAC™ networks, wireless devices areregistered on the network using a unique Personal Identification Number(PIN) associated with each device. In GPRS networks, however, networkaccess is typically associated with a subscriber or user of a device. AGPRS device therefore typically has a subscriber identity module,commonly referred to as a Subscriber Identity Module (SIM) card, inorder to operate on a GPRS network.

When network registration or activation procedures have been completed,the wireless device 100 may send and receive communication signals overthe communication network 110. Signals received from the communicationnetwork 110 by the receive antenna 154 are routed to the receiver 150,which provides for signal amplification, frequency down conversion,filtering, channel selection, etc., and may also provide analog todigital conversion. Analog-to-digital conversion of the received signalallows the DSP 158 to perform more complex communication functions, suchas demodulation and decoding. In a similar manner, signals to betransmitted to the network 110 are processed (e.g., modulated andencoded) by the DSP 158 and are then provided to the transmitter 152 fordigital to analog conversion, frequency up conversion, filtering,amplification and transmission to the communication network 110 (ornetworks) via the transmit antenna 156.

In addition to processing communication signals, the DSP 158 providesfor control of the receiver 150 and the transmitter 152. For example,gains applied to communication signals in the receiver 150 and thetransmitter 152 may be adaptively controlled through automatic gaincontrol algorithms implemented in the DSP 158.

In a data communication mode, a received signal, such as a text messageor web page download, is processed by the communication subsystem 170and is input to the microprocessor 128. The received signal is thenfurther processed by the microprocessor 128 for an output to the display126, or alternatively to some other auxiliary I/O devices 106. A deviceuser may also compose data items, such as e-mail messages, using thekeyboard 114 and/or some other auxiliary I/O device 106, such as atouchpad, a rocker switch, a thumb-wheel, or some other type of inputdevice. The composed data items may then be transmitted over thecommunication network 110 via the communication subsystem 170.

In a voice communication mode, overall operation of the device issubstantially similar to the data communication mode, except thatreceived signals are output to a speaker 111, and signals fortransmission are generated by a microphone 112. Alternative voice oraudio I/O subsystems, such as a voice message recording subsystem, mayalso be implemented on the wireless device 100. In addition, the display126 may also be utilized in voice communication mode, for example, todisplay the identity of a calling party, the duration of a voice call,or other voice call related information.

The short-range communications subsystem 102 enables communicationbetween the wireless device 100 and other proximate systems or devices,which need not necessarily be similar devices. For example, the shortrange communications subsystem may include an infrared device andassociated circuits and components, or a Bluetooth™ communication moduleto provide for communication with similarly-enabled systems and devices.

It should be understood that as used herein, terms such as coupled,connected, electrically connected, in signal communication, and the likemay include direct connections between components, indirect connectionsbetween components, or both, as would be apparent in the overall contextof a particular embodiment. The term coupled is intended to include, butnot be limited to, a direct electrical connection.

Numerous modifications and variations of the present disclosure arepossible in light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the disclosuremay be practised otherwise than as specifically described herein.

1. A method for execution in a multi-RAT (multi-Radio Access Technology)capable wireless device, the method comprising: maintaining aregistration history of all wireless network,RAT combinations throughwhich the wireless device has previously attempted to register with adata communication service registration point; upon an event triggeringnetwork registration, identifying a set of available wirelessnetwork,RAT combinations; selecting an available wireless network,RATcombination from the set of available wireless network,RAT combinationshaving regard to the registration history and a preferred network,RATcombination list stored at the wireless device; attempting to registerwith the data communication service registration point through theavailable wireless network,RAT combination that has been selected; ifthe attempt to register with the data communication service registrationpoint through the available wireless network,RAT combination that hasbeen selected is successful, receiving an update to the preferrednetwork,RAT combination list stored at the wireless device; and updatingthe preferred network,RAT combination list stored at the wirelessdevice.
 2. The method of claim 1, further comprising: updating theregistration history based on the attempt to register with the datacommunication service registration point through the available wirelessnetwork,RAT combination that has been selected.
 3. The method of claim2, further comprising: if the attempt to register with the datacommunication service registration point through the available wirelessnetwork,RAT combination that has been selected is unsuccessful,selecting an available wireless network,RAT combination from the set ofavailable wireless network,RAT combinations having regard to thepreferred network,RAT combination list and the updated registrationhistory.
 4. The method of claim 1, wherein maintaining a registrationhistory comprises at least one of: maintaining an identification ofnetwork,RAT combinations through which the wireless device haspreviously attempted and failed to register with the data communicationservice registration point; and maintaining an identification ofnetwork,RAT combinations through which the wireless device haspreviously attempted and succeeded in registering with the datacommunication service registration point.
 5. The method of claim 4,wherein: maintaining an identification of network,RAT combinationsthrough which the wireless device has previously attempted and failed toregister with the data communication service registration pointcomprises maintaining a blacklist identifying such network,RATcombinations; and maintaining an identification of network,RATcombinations through which the wireless device has previously attemptedand succeeded in registering with the data communication serviceregistration point comprises maintaining a registration list identifyingsuch network,RAT combinations;
 6. The method of claim 5, whereinselecting an available wireless network,RAT combination from the set ofavailable wireless network,RAT combinations comprises at least one of:avoiding selecting an available wireless network,RAT combination fromthe set of available wireless network,RAT combinations that is includedin the blacklist; and preferentially selecting an available wirelessnetwork,RAT combination from the set of available wireless network,RATcombinations that is included in both the preferred network,RATcombination list and the registration list.
 7. The method of claim 1,wherein: receiving an update to the preferred network,RAT combinationlist stored at the wireless device comprises receiving a MCC-dependent(Mobile Country Code-dependent) update to the preferred network,RATcombination list that is dependent on a MCC of the network,RATcombination that has been selected; and the MCC-dependent updateidentifies preferred wireless network,RAT combinations having the sameMCC as the network,RAT combination that has been selected.
 8. The methodof claim 7, wherein the MCC-dependent update further identifies at leastone preferred wireless network,RAT combination having a different MCCthan the MCC of the wireless network,RAT combination that has beenselected, wherein the MCC of the network,RAT combination that has beenselected and the at least one different MCC are associated with adefined region.
 9. The method of claim 1, wherein: the update to thepreferred network,RAT combination list is included as part of aregistration response from the data communication service registrationpoint; and receiving the update comprises receiving the registrationresponse.
 10. The method of claim 1, wherein the preferred network,RATcombination list stored at the wireless device identifies preferredwireless network,RAT combinations by MCC (Mobile Country Code), MNC(Mobile Network Code), RAT type and at least one of a LAI (Location AreaIndicator) and a RAI (Routing Area Indicator).
 11. The method of claim1, wherein the registration history identifies wireless network,RATcombinations by MCC (Mobile Country Code), MNC (Mobile Network Code) andRAT type.
 12. A computer readable medium having computer executableinstructions stored thereon for execution on a wireless device so as toimplement the method of claim
 1. 13. A multi-RAT (multi-Radio AccessTechnology) capable wireless device comprising: at least one antenna; amemory for storing a preferred network,RAT combination list and aregistration history of wireless network,RAT combinations through whichthe wireless device has previously attempted to register with a datacommunication service registration point; a multi-RAT capable wirelessaccess radio functionally connected to the at least one antenna that,upon an event triggering network registration, identifies availablewireless network,RAT combinations; a network,RAT combination selectorthat: selects an available wireless network,RAT combination from the setof available wireless network,RAT combinations having regard to theregistration history and the preferred network,RAT combination list;attempts to register the wireless device with the data communicationservice registration point through the available wireless network,RATcombination that has been selected; and if the attempt to register withthe data communication service registration point through the availablewireless network,RAT combination that has been selected is successful:receives an update to the preferred network,RAT combination list; andupdates the preferred network,RAT list.
 14. The wireless device of claim13, wherein the network,RAT combination selector updates theregistration history based on the attempt to register with the datacommunication service registration point through the available wirelessnetwork,RAT combination that has been selected.
 15. The wireless deviceof claim 14, wherein if the attempt to register with the datacommunication service registration point through the available wirelessnetwork,RAT combination that has been selected is unsuccessful, thenetwork,RAT combination selector selects an available wirelessnetwork,RAT combination from the set of available wireless network,RATcombinations having regard to the preferred network,RAT combination listand the updated registration history.
 16. The wireless device of claim13, wherein the registration history comprises at least one of: ablacklist of network,RAT combinations through which the wireless devicehas previously attempted and failed to register with the datacommunication service registration point; and a registration list ofnetwork,RAT combinations through which the wireless device haspreviously attempted and succeeded in registering with the datacommunication service registration point.
 17. The wireless device ofclaim 16, wherein the network,RAT combination selector is configured toat least one of: avoid selecting an available wireless network,RATcombination from the set of available wireless network,RAT combinationsthat is included in the blacklist; and preferentially select anavailable wireless network,RAT combination from the set of availablewireless network,RAT combinations that is included in both the preferrednetwork,RAT combination list and the registration list.
 18. The wirelessdevice of claim 13, wherein: the network,RAT combination selectorattempts to register with the data communication service registrationpoint by generating a registration request that identifies a MCC (MobileCountry Code) of the wireless network,RAT combination that has beenselected.
 19. The wireless device of claim 13, wherein the preferrednetwork,RAT combination list stored at the wireless device identifiespreferred wireless network,RAT combinations by MCC (Mobile CountryCode), MNC (Mobile Network Code), RAT type and at least one of a LAI(Location Area Indicator) and a RAI (Routing Area Indicator).
 20. Thewireless device of claim 13, wherein the registration history identifieswireless network,RAT combinations by MCC (Mobile Country Code), MNC(Mobile Network Code) and RAT type.